Ghinmi
Ok so I'm even more confused now. There's no limiter bushing installed. I took apart 2 other HEI units (a chevy and a pontiac) to compare the inner workings. The weights on all three are identical. The chevy unit had an identical center section but the pontiac had something different. The mr. gasket kit was completely different than everything else I have. To clear things up, here's a list of what I have.
3 sets of identical weights
1 set of mr. gasket weights
2 chevy style center sections
1 pontiac center section
1 mr. gasket center section
I cleaned up the holes in the mr. gasket center section and it fits now. I have tried combinations of all the weights and springs and nothing comes close to what it should (26-28* right?). The problem seems to be in the design of the weights and center section.
When I'm test fitting different weights and center sections, I'm comparing them to the plate with the teeth on it. There are 8 teeth evenly spaced, that means 45* between teeth. So my mechanical advance needs to be a little more than half that distance. The weights and springs I have are not coming close. Short of making my own center section (probably a bad idea), what else can I possibly do? I've tried all the weights and center sections I can and I'm getting nowhere. Help!
ironman_gq
how much base timing are you running?
AMX69PHATTY
The angle of advance seen at the dizzy is HALF what you'll get at the crank using a timing light.
15 degrees mech advance at the dizzy is 30 degrees at the crank,
cause the crank turns twice to the cam and dizzy turning only once.
ironman_gq
very good point!! :t:
Ghinmi
Ok so I finally got it figured out! :? I tore apart a third spare GM distributor and found a fourth different center piece. Slapped it in and I'm getting 35* total with 13* base timing. Does that sound alright? Thanks again for all your help guys!
AMX69PHATTY
yeah that sounds okay, 35* Total & 13* initial.
That would imply 11* mech adv in the dizzy and 22* at the crank
Is that from checking it running and using a dial back timing light ?
All 22* mech advance in by what rpm ?
May want to try as much as up to 40* total advance
but be careful and listen for detonation.
Ghinmi
I don't have a dial back light but I do have an accurate way of measuring the timing. When I had the balancer off, I marked 36* on it. Since 36* is 1/10 of the full circle, I measured the circumfrence of the balancer and divided by 10 to determine where to make the mark. IIRC, the measurement was 21.25" and 1/10 of that is 2.125 so that's where 36* ocurrs. When that mark hits the zero mark on the timing cover I know I'm at 36*. I can read the base timing by comparing it to the scale on the timing cover. Hope this makes sense. Probably should invest in a newer timing light anyways.
The mechanical is all in by 3000 exactly. It took me forever to match a set of springs that wouldn't advance at idle and still be all in at 3000 with this weight setup. Still seems like I should be able to get more than 22* advance though. I think it's alright for now until I get the carb dialed in 100%.
Just another random quick question, should I be running a higher stall converter with this setup? I'm currently geared 3.54 but I'm thinking of going with 3.92 or 4.10 when I switch to 2wd this winter. I will be running a 275/60/15 or larger drag radial depending on how much clearance I have when I spring under the rear axle. Should end up a little under 4000 lbs with me in it.
